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Microphone Pre-amp

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New Member
Hi everyone,

I need to set-up a microphone to plug into a video camera's audio line input.

What I've been looking at is using an electric mic and a pre-amp to amplify the mics signal to line level although I've got a couple of worries.
The specs of the camera's inputs are 320mV at about 47K ohms.

I figure that a simple pre-amp is the order of the day but need to hear the thoughts of someone that knows what they're talking about.
Any thoughts on a circuit design would also be very helpful.



Well-Known Member
Most Helpful Member
What is an "electric microphone"? Most modern mics are "electret" type.
The level is about 5mV so you need a preamp with a voltage gain of about 64.
Bias the microphone correctly with a low-noise supply then make a preamp with a low-noise opamp.
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